СРОЧНО РЕШИТЕ ПОЖАЛУЙСТА!!!

Найдите наибольшее и наименьшее значение выражения
0,5 cos α + 2 
Как решали тоже напишите пожалуйста)

 

какой объем кислорода потребуется для получения 75г оксида лития н.у. Помоги решить пожалуйста,пожалуйста,пожалуйста.У меня контрольная завтра..

раскройте скобки и приведите подобные слагаемые: 1/2 * (2х-6)+3*(х-1) 
(с решением плиииз***) 

Стороны прямоугольника 2 дм и 1 дм 5 см. Вычислить площадь и периметр прямоугольника. по действием

ЗАДАЙТЕ 5 ВОПРОСОВ К ТЕКСТУ Three men came to New York. They arrived at a very large hotel and took a room there. Their room was on the forty-fifth floor. In the evening the three men went to the theatre and came back to the hotel very late. "I am very sorry," said the clerk of the hotel, "but our lifts aren't working tonight. If you don't want to walk upstairs to your room we will make beds for you in the hall." "No, no," said one of the three men. "No, thank you. We don't want to sleep in the hall. We will walk up to our room." Then he told his two friends, "It won't be easy to walk up to the forty-fifth floor, but I think I know how to make it easier. On our way to the room I will tell you some jokes. Andy willjsing us some songs. Then Peter will tell us some interesting stories." So they began to walk upstairs to their room. Tom told them many jokes, Andy sang some songs. At last they came to the thirty-fourth floor. They were tired and decided to have a rest. "Well," said Tom, "now it is your turn, Peter." "I will tell you a sad story," said Peter. "We have left the key to our room in the hall."